How to adjust monitor's backlight brightness in Windows
Update - 2015-10-30
ScreenBright seems discontinued, but as @wrongusername suggested, pangobright might be an alternative.
The solution I am using right now
I found enable DDC/CI option in my displays' settings. The ScreenBright program was able to modify it, although I think it's GUI is quite terrible and easy to break you custom settings. My screens also flicker a lot when changing brightness. Nevertheless, it has a commandline interface, which is much better. Especially when you create your own GUI (which is around 5 minutes in C#) or use plain Windows shortcuts.
Old setup
As a side note to the Dell brightness change - I can confirm that it also did work for me. My setup was:
- Dell Latitude laptop (5520 I believe)
- Dell Docking station (the extended version)
- 2xDell u2412m screens, connected via DVI
The laptop itself had a built-in GPU (Intel HD2500). In its software there was a tab called "monitor settings", iirc. It did indeed communicate with the displays and somehow change their built-in brightness settings. I weren't able to do much more (change profiles, for example), and it took quite a while to "initialize". There was also a 2-3 second delay between the setting of the brightness and actual change. I guess it was mostly due to the screens, which changed brightness gradually.
I've updated my PC to the regular workstation, and unfortunately I wasn't able to find similar setting in the NVidia control panel.
EDIT: It seems that my previous setup used DDC.
I found ClickMonitorDDC from a recommendation on Superuser:
softMCCS from ddc-ci.com allows lots of control but it's too low level technical for regular use.
Just to control brightness and contrast I'm using http://clickmonitorddc.bplaced.net (Windows).
answered Mar 15 '15 at 23:09 aland
Desktop LCD monitor which allows backlight to be controlled in software
ClickMonitorDDC is a portable freeware tool to adjust brightness or contrast of a DDC compatible monitor
http://clickmonitorddc.bplaced.net/
It's the most user-friendly application that I've tried.
You can quickly jump to any brightness and contrast number that is a multiple of 5, and then finely adjust.
There are also hotkeys, and command line commands.
e.g.
b20 c30
Brightness 20 contrast 30.
ClickMonitorDDC also allows you to jump to a volume.
With the default Windows 10 volume control, it's hard to see the exact volume number that you will jump to.
ClickMonitorDDC has 20 volume buttons that are each a multiple of 5, and they go from 0 to 100.
I also tried this recommendation in combination with ClickMonitorDDC:
Flux v3.10 has additional functionality to control actual brightness using hot-keys Alt+PageDown and Alt+PageUp.
answered Jun 25 '14 at 17:25 Karan
Flux is a filter, and it can get you darker than ClickMonitorDDC and your monitor will by themselves.
EDIT: April 24 2018
I've noticed that ClickMonitorDDC might not work on all monitors.
Alternatives include Desktop Dimmer (https://github.com/sidneys/desktop-dimmer) or PangoBright (https://www.pangobright.com/)
The application Display Tuner can control the brightness for many different LCD/CRT monitors.
However, if backlight is a separate setting on your monitor, you might be out of luck.